Design and performance analysis of a grid connected PWM-VSI system

Pulse-width modulation (PWM) voltage source inverters (VSIs) are favorable interface devices to the power grid for renewable energy systems. This paper deals with the design of the LCL-filter and inverter for the grid-connected VSI. A complete design procedure for both reactive and passive components of LCL-filter is demonstrated with a new iterative approach in selection of the filter inductors. The design process for a two-level VSI is clearly illustrated through an example and the dynamic response is investigated under insufficient and sufficient damping cases. In this study, comprehensive analyses have been conducted to maximize the performance and efficiency. For this purpose, the line current total harmonic distortion (THD) and power factor performance of the designed system is assessed under various load conditions. Besides, the effects of the utilization of different PWM patterns on efficiency are compared and contrasted under different loads with altering switching frequencies. Simulation results validate theoretical findings throughout the design phase.